Finding things in the universe requires an understanding of scale. We live on a planet, orbited by a moon, orbiting the sun, with several other planets, in a cluster of stars, on the edge of a galaxy, with billions of other galaxies scattered around.
Stars come in all varieties. Careful study reveals stars with diverse temperature, mass, brightness, and luminosity. They are also different distances from the Earth, and their apparent brightness depends on their own luminosity and their distance away from us.
Fusion is the process of squeezing nuclei together. When they fuse into a single nucleus, energy is released. We see gravity do this in the sun; we have made Hydrogen bombs; we hope that lasers will be able to fuse hydrogen for commercial power plants.
Stars radiate energy in all directions, and the intensity of that radiation weakens as the distance grows. Telescopes collect radiation that was spread out, and focuses it together on a single spot, so the radiation can be studied in greater detail.
As stars use up their fuel, they change. The end results of this process can be pretty tame or pretty spectacular! This topic leads us to some exotic astronomical objects: red giants, white dwarfs, neutron stars, and black holes.
Table of Contents
Benchmark Assessments
SS1 : Scale of the Universe
Finding things in the universe requires an understanding of scale. We live on a planet, orbited by a moon, orbiting the sun, with several other planets, in a cluster of stars, on the edge of a galaxy, with billions of other galaxies scattered around.SS2 : Stellar Variety
Stars come in all varieties. Careful study reveals stars with diverse temperature, mass, brightness, and luminosity. They are also different distances from the Earth, and their apparent brightness depends on their own luminosity and their distance away from us.SS3 : Stellar Fusion
Fusion is the process of squeezing nuclei together. When they fuse into a single nucleus, energy is released. We see gravity do this in the sun; we have made Hydrogen bombs; we hope that lasers will be able to fuse hydrogen for commercial power plants.SS4 : Telescopes
Stars radiate energy in all directions, and the intensity of that radiation weakens as the distance grows. Telescopes collect radiation that was spread out, and focuses it together on a single spot, so the radiation can be studied in greater detail.SS5 : Death of a Star
As stars use up their fuel, they change. The end results of this process can be pretty tame or pretty spectacular! This topic leads us to some exotic astronomical objects: red giants, white dwarfs, neutron stars, and black holes.